Effects of dietary supplementation of different oils and conjugated linoleic acid on the reproductive and metabolic aspects of male mice.

The present study was carried out to examine first, if diets enriched with 320 g of the base diet with common dietary oils including fish oil, olive oil, hydrogenated sunflower seed (H-SFS) oil, flaxseed oil and sunflower seed oil (SFS) could induce weight gain and alter reproductive and metabolic characteristics of male mice. Second, whether the addition of conjugated linoleic acid (CLA, 10% of the diet) could ameliorate any negative effects. In this cross-sectional study, 90 four-week-old male NMRI mice were used in two consecutive experiments. A high level of dietary oils negatively affected some reproductive and metabolic characteristics of male mice (p < 0.05), specifically, sunflower seed oil enrichment resulted in higher HDL levels and apoptosis of germinal epithelial cells. An olive oil-enriched diet caused an increase in plasma triglyceride concentrations and germinal cell apoptosis, as well as a decrease in sperm concentration and perturbed spermatogenesis. When CLA was fed in conjunction with dietary oils it successfully mitigated some of the negative reproductive and metabolic characteristics. We conclude that male reproductive processes are affected by high dietary oils, even before signs of obesity are evident. Inclusion of dietary CLA may provide some benefit to offset negative effects, although further studies are required.

Effects of supplementation of tris-egg yolk extender with different sugars and antioxidants on freezability of ram semen.

This study was designed to determine the effects of the combined addition of different levels of certain sugars (trehalose, sucrose and raffinose) and antioxidants (vitamin E, C and taurine), in Tris-egg yolk extender on frozen-thawed ram semen parameters. Semen samples were collected from five healthy, mature and fertile Iranian Afshari rams, twice a week for 8 weeks. Selected samples were pooled and diluted with a Tris-egg yolk extender containing different levels of sugars and antioxidants. In Experiment 1, different levels of trehalose (0, 50 and 100 mM) were tested with different levels of taurine (0, 25 and 50 mM), vitamin E and C (0, 1 and 2 mM). In Experiment 2, different levels of sucrose (0, 60 and 80 mM) were tested with different levels of taurine (0, 25 and 50 mM), vitamin E and C (0, 1 and 2 mM). In Experiment 3, different levels of raffinose (0, 5, 10 mM) were tested with different levels of taurine (0, 25 and 50 mM), and vitamin E and C (0, 1 and 2 mM). In Experiment 4, the selected extenders of experiments 1, 2 and 3 were compared statistically with control (no selected sugar and antioxidant) extender. The results of experiments 1, 2 and 3 revealed that the highest frozen-thawed sperm parameters were recorded for the selected extenders containing 100 mM trehalose +2 mM vitamin E (T100E2), 60 mM sucrose + 2 mM vitamin E (S60E2) and 10 mM raffinose + 2 mM vitamin E (R10E2), respectively. The results of experiment 4 revealed that the post-thaw sperm total motility in T100E2 (62.41 ± 2.41%), S60E2 (59.52 ± 1.91%) and R10E2 (58.33 ± 2.00%) was higher than that of the control extender (46.00 ± 1.79%; P ≤ 0.05). Similarly, the progressive sperm motility in T100E2 (57.18 ± 1.96%), S60E2 (57.49 ± 1.94%) and R10E2 (55.03 ± 2.99%) was also higher than that of the control extender (41.20 ± 1.70%; P ≤ 0.05). Post-thaw sperm viability in selected extenders of T100E2 (65.20 ± 2.67%), S60E2 (62.00 ± 2.07%) and R10E2 (61.80 ± 2.46%) was higher than that of control extender (51.00 ± 1.88%; P ≤ 0.05). In conclusion, the addition of 100 mM trehalose, 60 mM sucrose and 10 mM raffinose combined with 2 mM vitamin E in Tris-egg yolk extender significantly improved frozen-thawed ram semen parameters.

Effects of supplementation of Tris-egg yolk extender with royal jelly on chilled and frozen-thawed ram semen characteristics.

This study was conducted to examine the effect of supplementation of Tris-egg yolk extender with lyophilized royal jelly (RJ) on chilled and frozen-thawed ram semen parameters. Ejaculates were collected by artificial vagina from 4 mature rams, twice a week for 4 weeks. Only samples with motility of ≥70% were included, pooled and divided into four equal parts and then diluted in extenders with various concentrations of RJ (0, 1, 3 and 5%, vol/vol) to a final concentration of 200 × 106 sperm/mL and was incubated at 37 °C for 30 min and were subsequently evaluated. After equilibration of extended semen for 2 h at 4 °C, some semen samples were packed in 0.25 mL plastic straws. Then, the straws were frozen in the liquid nitrogen vapor phase for 15 min and stored at -196 °C in liquid nitrogen. The frozen straws were thawed in warm water (37 °C) for 30 s and evaluated; whereas, other semen samples were stored in the refrigerator (4 °C) up to 7 days. The chilled samples were kept in water bath (37 °C) for 5 min and then were evaluated. After dilution, the lowest and highest sperm total abnormality was recorded in 3 and 5% RJ supplemented groups, respectively (P < 0.05). The chilled sperm total motility and membrane integrity were significantly (P < 0.05) higher in 3% than those in 0% and 5% RJ supplemented groups. The chilled sperm progressive motility and viability was significantly (P < 0.05) higher in 1 and 3% than those in 0 and 5% RJ supplemented groups. The frozen-thawed sperm total motility, progressive motility, membrane integrity and viability were significantly higher in 3% RJ supplemented group (P < 0.05). In conclusion, supplementation of Tris-egg yolk extender with 3% lyophilized RJ had a protective effect on chilled and cryopreserved ram spermatozoa.

Design and implementation of elliptical mantle cloaks for polarization decoupling of two tightly spaced interleaved co-frequency patch array antennas.

In this paper, we utilized the method of mantle cloaking to decouple/isolate two densely packed interleaved patch array antennas operating at the same frequency but with orthogonal polarizations. To reduce mutual coupling between the adjacent elements, vertical strips, as a type of elliptical mantle cloaks, are located in close proximity to the patches. At the operating frequency of f0 = 3.7 GHz, the edge-to-edge spacing of the elements of the two interleaved arrays is less than λ0/80 (1 mm) and the center-to-center spacing of each array element is 0.7 λ0 (57 mm). The proposed design is implemented using 3D printing technology, and its performance in terms of return loss, efficiency, gain, radiation patterns, and isolation is measured for evaluation. The results show the radiation characteristics of the arrays are perfectly retrieved after cloaking similar to the isolated arrays. Decoupling tightly spaced patch antenna arrays on a single substrate paves the way to achieve miniaturized communication systems with full duplex operation or dual polarization communication.

The effect of dietary pioglitazone supplementation on milk yield, insulin sensitivity and GH-IGF-I axis in Holstein dairy cows during the transition period.

BACKGROUND: High-yielding dairy cows develop insulin resistance during late gestation associated with disruption of the growth hormone (GH)-insulin-like growth factor (IGF)-I axis and cause metabolic and reproductive disorders. OBJECTIVE: This study aimed to determine the effects of dietary pioglitazone (PIO) supplementation as an insulin sensitizer agent on milk yield, plasma metabolite status and GH-IGF-I axis in transition Holstein dairy cows. METHODS: Twenty multiparous cows were randomly assigned into two experimental groups (n = 10 animals per group) and either fed with a basal diet (control) or the basal diet supplemented with 6 mg PIO/kg body weight (BW) from day 14 before parturition to day 21 postpartum. The BW and body condition score (BCS), non-esterified fatty acids, beta-hydroxybutyrate (BHBA), insulin, glucose, GH and IGF-I concentrations, milk production and composition were measured weekly. RESULTS: BW and BCS losses were lower in PIO than in control cows (p < 0.05). The percentage and amount of milk fat were decreased, and the amount of protein increased only in the first post-calving week in the PIO-treated cows compared to the control (p < 0.05). Dietary PIO supplementation increased glucose concentration at calving, but insulin concentration was increased at calving and in the first post-calving week (p < 0.05). Plasma concentrations of IGF-I and the ratio of IGF to GH were increased in the PIO group (p < 0.05). The mean revised quantitative insulin sensitivity check index with BHBA, as an insulin sensitivity index, was greater in PIO-supplemented cows (p < 0.05). CONCLUSIONS: Our results showed beneficial effects of PIO supplementation on improving insulin sensitivity and the GH-IGF-I axis that may cause lower negative energy balance and better metabolic and health status in transition dairy cows.

Sublethal Xanthine Oxidase Stress Prefreezing of Bull Sperm Improves the Post-Thaw Functionality and Fertility Potential Parameters.

Oxidative stress during cryopreservation causes mechanical, biochemical, and structural damage to the sperm, leading to lower viability and fertility potential. In recent years, a novel method based on the use of mild stress for preconditioning of sperm before cryopreservation has been applied to improve the quality of thawed sperm, although its molecular mechanism remains unknown. In this study, we investigated the protective effects of sublethal oxidative stress by xanthine oxidase (XO) on thawed bull sperm performance through modulations of mitochondrial uncoupling protein 2 (UCP2) expression. Semen samples were collected from six bulls, then mixed and divided into four aliquots: frozen control (XO-0) and frozen groups treated with different concentrations of XO, 0.01 µM (XO-0.01), 0.1 µM (XO-0.1), and 1 µM (XO-1). Thawed sperm were evaluated for motion parameters, viability, acrosome integrity, mitochondria activity, membrane integrity, and UCP2 expression. A significant increase of total motility and viability rate was observed in XO-0.1 compared with other frozen groups (p < 0.05). The highest percentage of progressive motility was in XO-0.01 and XO-0.1 compared with other groups (p < 0.05). Moreover, a significantly higher level of sperm mitochondrial membrane potential and membrane integrity was observed in XO-0.1 (p < 0.05). We also found the lowest percentage of sperm mitochondria activity in XO-1 (p < 0.05). In addition, the highest expression of UCP2 was observed in XO-1 (p < 0.05). Our findings suggest that stress preconditioning of bull sperm before cryopreservation can improve thawed sperm functions, which might be mediated through an increase of UCP2 expression.

Effect of Exogenous Progesterone or Flunixin Meglumine After AI on Serum Progesterone Concentration and Pregnancy per AI in Lactating Dairy Cows.

The objective of this study was to determine the effect of post AI administration of exogenous progesterone (P4) or a prostaglandin F2α (PGF2α) synthesis inhibitor agent on serum P4 concentrations and pregnancy per AI (P/AI) in lactating dairy cows. Eighty lactating cows were randomly allocated to one of four treatment groups: 1) CON (control), received 5 mL of saline solution on d 6 and 14 post AI; 2) IP4 (injection of P 4), received 125 mg of P4 im on d 6 and 14 post AI; 3) CIDR, received a controlled internal drug release insert containing 1.38g of P4 from d 6 to 20 post AI; and 4) FM (Flunixin Meglumine), received 0.625 g of Flunixin Meglumine, a nonsteroidal anti-inflammatory drug, twice daily on d 15 and 19 post AI. Blood samples were taken on d 0, 6, 14, 17 and 20 post AI to determine P4 concentrations. Transrectal palpation was performed between 40 and 45 d post AI to determine pregnancy status. All treatment groups (i.e. IP4, CIDR and FM) resulted in greater serum P4 concentration on d 17 and 20 post AI compared to CON (P < 0.05). Cows given a CIDR insert had greater concentrations of P 4 on d 17 and 20 than IP4 and FM cows (P < 0.05). However, no significant difference was found between IP4 and FM groups for serum P4 concentrations. The P/AI was greater (P < 0.05) in CIDR-treated cows (55%, 11/20) than CON (25%, 5/20), and intermediate in IP4 (40%, 8/20) and FM (35%, 7/20) cows. In summary, treatment with exogenous P4 (i.e. CIDR and IP4) or FM increased serum P4 concentrations in lactating dairy cows. However, results suggest that only CIDR administration would improve P/AI.